Valve mechanism for fluid motors



2 Sheets-Sheet l Dn O T N E V N ATTORNEYS M .Aln S N E D R 0 N S R Dn 0 N N. NORDENSTAM VALVE MECHANISM FOR FLUID MOTORS FIG. I.

Sept. 11, 1956 Filed March l, 1954 Sept' 11, 1956 N. NoRDENsTAM 2,762,344 VALVE M EOHANISM FOR FLUrD MOTORS I Filed March l, 1954 2 Sheets-Sheet 2 FIG. 6. l FIG. 8

A INVENTOR NORRIS NORDENSTAM Wmv/014A.

ATTORNEYS v y e K '2,762,344 VALVE MncHANI'sM FOR FLUID MOTORS Norris Nordenstam, Riverside, Calif'. n 'y Application March 1, 1954, Serial No. 413,232 s Claims. (Cl. 'ui- 164) This invention relates to huid-operated motors such as those embodying a pivoted reciprocating vane and commonly used for operating wind-shield wipers on vehicles.

A disadvantageous feature of fluid motors of lthe type indicated resul-ts from Ithe employment therein of snap action valve mechanism with consequent full pressure dilerential being present on the vane throughout the entire stroke thereof. -As a result, the direction of the vane is suddenly reversed at the end of each stroke and 4this causes whipping of the driven parts, such as t-he windshield wiper blades.

An object of my invention is to provide novel means `for controlling the flow of iluid -to the piston or vane of a uid motor of thetype above mentioined, in a manner -to cause the vane to sl-ow down as it appro-achesthe end of its stroke and to relatively slowly travel at the beginning of its stroke, thereby preventing rapid reversals of the motion andthe consequent rapid whipping of the object driven by the motor.

A further object is to provide means adapt-able for incorpora-tion into a standard type of windshield wiper motor to control the ilow of air to the motor in a manner such that 'the supply of air is limited or restricted at the beginning and end of each stroke of the vane.

A further object is to provide a simple means for accomplishing the above objects which can be readily manufactured and embodied in a windshield wiper type of iiuid motor but which also may have other uses.

These and other objects will -be apparenttmm the drawing and-the `following description. Referring Ito the drawing:

Fig. l is a side elevationalview, partly broken away, of a windshield wiper fiuid motor;

Fig. 2 is an enlarged fragmentary face View, partly in sec-tion, of a portion of the valve mechanism;

Figs. 2A and 2B are enlarged sections on lines 2A-2A, 2B 2B, respectively of Fig. 2;

Fig. 3 is an enlarged sectional view on line 3 3 of Fig. 2;

Fig. 4 is a perspective View of a cam member;

Fig. 5 is a perspective view of a cam-follower control element;

Figs. 6 and 7 are views similar to Fig. 2 but showing Ithe parts in different posi-tions;

Figs. 8 Iand 9 are enlarged sectional views on lines 8 8 and 9 9, respectively, of Fig. 6;

Figs. l() and 1l are enlarged sectional viewson lines 10 10 and Il ll, respectively, of Fig 7;

Figs. 12 and 13 are face views of a modified form of valve element.

More particularly describing 'the invention, numeral 11 generally indicates a uid motor of the ltype used for actuating Windshield wipers on automobiles. The motor has a housing12 which defines an arcuate vane cornpartment 13 in which a vane or piston 14 reciprocates, being 'mounted upon a rock `Shaft 15 suitably j'ournaled in the housing.

Uftiffl Se@ Patent 0 Part of the housing extends forwardly and centrally on one lside to provide a valve housing portion 17 which includes the enclosing wa-ll 18 and a partition -wall 19. A filter chamber 20 is provided at one 'end containing fibrousV material 21, the Iair supplied to the motor passing 4therethrough land through holes 19 Iand 18' in the walls. A :cover 22 is fitted to wall 18.

Ihe motor has a tubular ditting 23 lto which `a hose 24 can be attached for `connecting the motor to a source of suction, such as the intake manifold of a motor, -and tube 23 communicatesv through the housing of fthe motor with a supplypassagel'. f

The housing provides ,a valve face `26 against which is positioned-a valve 27,*pivotally mounted ona tube 28 which forms-part ofthe passage 23.

The valve face 26 has ports 30a and 30b which communicate respectively with the opposite ends of the vane compartment 13. In the functioning Iof conventional devices of this nature, valve 27 connectsone yof the ports 30a, 36b with the central passage 2,3', which is normally at a pressure below that of atmospheric, thereby serving to evacuate air from one end of the vane compartment. At the same time the valve member uncovers ror exposes `the other port 30a, 30b to permit air to enter therethrough'to 'the opposite Iside of the vane.

The valve is operated 'by a kicker mechanism including 'a kicker disk 32, a link 33, and a compression spring 34, "the kicker disk 32 being suitably recessed at 35 for actuation by a portion 37 on the rock shaft 1S 'in a manner well known in the art.

It is a particularv feature of my invention that I provide a special type of valve and control means therefor whereby Yto limit the flofw of air to the motor at the beginning of each stroke of the vane. v.The valve 27 has an interna-l passage 40 communicating with passage 23 and terminating at each end in valve ports 40aand 4011. Also, the valve member is provided with holes 41a and 41b adjacent the ports 40a and 40h, the holes 41a and 41b being Of relatively limitedcrossseot-ional areaV and considerably smaller than the ports 40a and 40b. When the valve is fully open, such as shown inFig.V 2, one port in the valve (40a) `registers with one port (30a) inthe face 26. The other;v port in -face -26 (30b) is entirely exposed, thereby permitting a full supply of air to pass through port 30b, the kicker disk being appropriately undercut or recessed vat each side vat Y32' sol as not to closethe ports 30a, 30b when overlying them. This is the position that the parts occupy during movement Of the vane through the major portion Off its stroke. A-s the vane Iapproaches the end of its stroke the kicker member gradually moves to the position shown in Fig. 6, causing the valve member 27 to move with it to the positionof Fig. 6. In consequence, the port 30b -is covered by the valve member and hole 41b therein registers with the port so that only a limited amount of air is passed through the port, or in other words, the supply of air is restricted. A-s the vane progresses toward the end of the stroke, the kicker mechanism snaps over center and moves the valve memlber from the position of Fig. 6 to that of Fig. 7 which is an intermediate or arrested position, the kicker disk being held by a control element 62, later to be described. In this position. the portion Iof the valve having hole 41a .covers port 30a while the port 30b is in communication with the port 40b of the valve. In consequence, the lair iow tol-the motoris restricted lby the opening 41a of limited cross section as the vane rbegins a new stroke. After the vane has moved through several degrees the kicker disk is released and `the valve member -isjmoved to the extreme position which comparable to that shown in Fig.- 2 but opposite thereto, with consequent full pressure differential on the vane. As the yvane approaches the end of Patented Sept. 11, 1956 its strokerit causes the kicker mechanism and the valve member to move back toward center to a position com parable tothat shown inFiig. i5. i n

i iileaiis foi 'llliiig the rife'r'rint `of "the `Va`lve i iriestitg,`its inovieiit to prevent it sii'appirl'g' to 1A operi er esserne position fas it passes over `center, site would neinauyeeeuf under the ifmuenee 'of the kicker mechanism, includes Fa darn element 51 firitionally mounted on noli-ew stub snaftvsz receiving the end of the Irock shaft 15 4and having recessed portions 53 adapted to t ovi-p''rt 37 'ond-he ro'ek 4'sl'1`iaft-. The ymember 5l induites a peripnerarn'riige s4 and it Yand the adjacent portions' of the in e' lil'av'e oppositely disposed recesses s6; The .diskea'rfiies a tongue' sr 'wh-ith abats housing portion-s 58, limiting movement of the-bain. In this connection it may be pointed but 'that the cam `and shaft 52 fare relatively fiictioal-ly movable, the cam being held Ibetween plates 59 and '60 with a spring washer '61 between plate 60 and the Thus slippage may occur between the cani and shaft when the tongue abuts the housing portions 58.

In `conji`111'c` ti`or t the "cam member 51 I provide a control element 62, which consists of a -flat "sp-ring mounted centrally, 4as by rivetl63-, to the housing Wall 18. This member 'is generally U-shaped and has two legs 64, eac-h of ywhich has an intu'rned ilan'g'e 65 across about half its Width at the inner side thereof. The liang'es 65 would normally be in the path of fthe 'respective shoulders '67 0"11 'the kicker disk, limiting movement thereof -as best shown in Fig. 7. However, the position of flanges 65 is controlled iby the Ycam disk 54 upon which the straight or 'outer portions 'of legs l64 ride. Thus, when the cam disk is in the position shown in Fig. l, the spring legs of the tnember v62 'are held outwardly and do not .interfeie with 'the kicker member 32, `permit'ting vthe kicker mmiberf'nd-valye vZ7 'to "move to the extreme position aslshwn iin 2. Howeverpas thezcam disk is rotated by -tlre movement of 'the 'vane 14, the lett leg 64 of elfnnt '62 falls minto the recess 56 0n 'the loam disk '54, therebypos'itibning the lefg fange '65 in the .path :of the 'shoulder "67 of Ilciele'r member 32 'se that, when that in'ember subsequently snaps yover trom the position of Fig. 76, it is arrested by- 'the 7appropriate 'leg portion 64 in the position shown in Fig. 7. 'As ithe vane begins aiw strokefit tiins #the "cam disk 54 back toward Vthe positin of Fig Yl, moving *the left leg`64 outwardly, permitting the kicker member to rnove the valve to extreme-or"fullpenpsition l vIt willbe'apparent Lfro'm the `above thatmy mechanism accomplishes 'the various "objects set -forth above, and that', '-*inparticulan "1 "have v:provided "automatic `means for `restricting TloW `Tof 'air t'o :the vane x.at 'the end and "begin- In Figs l2 and tl3 l lshow another 'forth o-'f 'valve 'inember, rdesignated 75 having la 'central 'suction passage v76, 4*lV/"of key-slot "shape 7and "connecting passages 18. Inthis :form of theriinventionthe `airdlowis restricted Ain the intermediate lpositios lof"=the valve comparable `to tli ei'f iFigs. `6 and 7":by the lise fof p't'ntslof vreduced ciossrseet-ionaliereaat oii'epend. Fig. V12 Iillustrates the full openpostion. Fig. '13 illustrates the position f tle y'f'valve interller "in *an intermediatefposition, which rr'iay @be rei'tlirfthe comparable @to that SioffFig. `6 where theikiekerneellanism Ihals 'approached but not sappd *passed center for 'the position comparable to that ofi-Fig. lwhereltlrekielcer'diskis heldli'y the vcontrol in'ean-s. Intllefptisitionoflig.i3, 'theYnarr-ow end `p`oru'n'ferre efipetts 11i-S shown inv .registrationtvitntne port 30a. Fhusfnll suction isrnetjsupplied. The 4port sobfis'einieteiy menthe ends "75av of tires/atv@ mem- 4be'ii biingiundrcut'at79J s nottoiloe theiports it'rh'eh-Yoverlyii-g*"tl'ie'r't'a. It @be apparent, `therefore e valvefwhenin ermetliate positiondoes `not "Vide i" ''iii-aii'fr ffllil "rSS-S'rotiol `area of qis'loti'on Although .I have illustrated and described a preferredl Lform of my invention, I contemplate that various changes v a piston reciprocabile therein, said motor having a uid supply-passage and a pair of piston compartment passages communicating, respectively, AVwith the ends of said compartment and each terminating in a port, valve means comprising a mvably 'mounted Valve member 'adapted to oscillate between twoV ext-remepositions alternately to cover and connect one of said prt's'to said supply passage and expose the other of said ports to atmosphere, snap-action oscillating knicker means to oscillate the valve member in timed relation to movement of the piston, and means for temporarily airestirfg said knicker means short of its full travel in each direction whereby to arrest said valve member short of each of said extreme positions on each movement thereof, said valve member, when arrested, connecting `one of said ports to lsaid supply passage and having means partially closing the other port.

'2. Valve means for a fuid "motor as -Set forth in claim l in which said valve member comprises an elongated, centrally pivoted body having a portat 'each end for registifation, alternately, with the ports at the 'ends of the piston compartment passages, and in which the means for partially closing said other port comprises a lateral, apertured 'projection at each end of 'the body adjacent the p'ts hri'l.

3. In "a fluid 'motor having fa'piston compartment and a piston reciproc'nble therein, said 'motor having a uid supply passage 'and -a pair ofpiston compartment passages communicating, respectively, Vwith fthe ends of said comp'atment and 'each terminating lin a port, valve means comprising a pivotally mounted valve member adapted to oscillate lbetween two extreme positions alternately to cover and connect one of saidports lto said supply passage and 'expose 'the other of said po'rts to atmosphere, means to oscillate the valve member in timed 'relation to movement of the piston, said last mentioned means comprising a snap-action kick'er mechanism including an oscillatable kicker member "engaging said'v'a'lve member for imparting movement thereto, 'a cam 4movable in timed `relation with the piston, a cam-follower element e'ngage'able with the cam, and'interengagin'g means on `said cam-follower element and said lkicker 'member 'engage'able in certain positions of said cam-follower element to arrest 'said kicker member'short of'each 'of 'said two extreme positions thereof, said valve member being-so 'shaped as to connect one of said'ports tosaid supplypassage and partially/fclose said other port "when said kicker is in arrested position.

4. In a tiuid 'motor 'having :a reciprocable 'vane-type piston and a rock shaft journalling the lpiston, vsaid motor having'a 'fluid supply passage -and apair of piston 'compartment passages communicating, respectively, with the ends of said compartment andfeachterminating in aport, valve means comprising-'a pivotally mounted valve member adapted to oscillate between two extreme positions alternately tofcover and connect-'one of said-ports to-said supply passage and cxposethe other of said ports to atmos'phere, -meanstooscillate the valve member in timed relation to movement of'the piston, said last mentioned means comprising a `snap-action Akicker mechanism Iincluding an oscillatable'kicker member engaging said Avalve member'for imparting movement thereto, ia cammounted on said rock shaft for movement therewith, a cam-follower-element engageable with-'said cam and, in certain 'positions of lsaid cam Withsai'd kicker member to arrest -said kicker membershort yof full frno'vementthereof, said valve member being so lsha'pe'd last'o connect one of said .portstosaid supply passage and partially close said other port 'when i said kicker l`is `fax-rested.

5. Valve means as set forth in claim 4 in Whichfsaid cam-follower element comprises a U-shaped spring having a pair of legs engaging, respectively, opposite sides of said cam, said legs being formed to provide thereon portions engageable with said kicker member.

6. In a uid motor having a piston compartment and a piston reciprocable therein, said motor having a fluid supply passage and a pair of piston compartment passages communicating, respectively, with the ends of said compartment at one end and terminating in a motor port at the other, a pivotally mounted valve member having an internal passage communicating with said supply passage and having a valve port at each end of said internal passage, said valve ports being elongated generally in the direction of movement thereof and each having a Wide end and a narrow end, said narrow end being of less Width than the diameter of a motor port, said valve being adapted to oscillate between two extreme positions in either of which the Wide end of one valve port registers with a motor port leaving the other motor port exposed snap-action oscillating kicker, means for oscillating said valve member in timed relation to movement of the piston, and means for temporarily arresting said kicker means short of its full travel in each direction whereby to arrest said valve member short of said extreme positions, said valve member, when arrested, having the narrow end of its port overlying one of said motor ports leaving the other motor port exposed.

7. In a uid motor having a reciprocable vane-type piston and a rock shaft journalling the piston, said motor having a uid supply passage and a pair of piston compartment passages communicating, respectively, with the ends of said compartment and each terminating in a port, valve means comprising a pivotally mounted valve member adapted to oscillate between two extreme positions alternately to cover and connect one of said ports to said supply passage and expose the other of said ports to atmosphere, means to oscillate the valve member in timed relation to movement of the piston, said last mentioned means comprising a snap-action kicker mechanism including an oscillatable kicker member engaging said valve member for imparting movement thereto, a cam mounted to be driven by said rock shaft, a kicker control member engageable with said cam, and, in certain positions of said cam, with said kicker member to arrest said kicker member short of full movement thereof, said valve member being so shaped as to connect one of said ports to said supply passages and at least partially expose said other port and further to restrict ow of fluid through one of said ports when said kicker is arrested.

8. In a uid motor having a piston compartment and a piston reciprocable therein, said motor having a fluid supply passage and a pair of piston compartment passages communicating, respectively, with the ends of said compartment and each terminating inv a port, valve means comprising a movably mounted valve member adapted to oscillate between two extreme positions alternately to cover and connect one of said ports to said supply passage and expose the other of said ports to atmosphere, snap-action oscillating kicker means to oscillate the valve member in timed relation to movement of the piston, and means for temporarily arresting said kicker means short of its full travel in each direction whereby to arrest said valve member short of each of said eX- treme positions on each movement thereof, said valve member, when arrested, connecting one of said ports to said supply passage and exposing the other of said ports, said valve member in said arrested position, providing means restricting flow through one of said ports.

References Cited in the tile of this patent UNITED STATES PATENTS 583,587 Westinghouse June 1, 1897 2,563,068 Rappl et al. Aug. 7, 1951 2,670,720 Bitzer Mar. 2, 1954 

